I am quite ignorant about domestic politics. There is a very rough and unsupported theory, saying that in Taiwan the China factor divides the basic political camps. There are no Left or Right, Labor or Progressive or Conservative in general. The independence or reunification issue is the basic divide. Which is a nationalism issue I guess.
On ethnic issue, the population can be divided into 5 or 4 groups. The majority are Han Chinese people. The so-called "Chinese Chinese". they can be subdivided into 3 groups by languages: Hoklo, Hakka, and Mandarin. The first two are called natives. They came to Taiwan during Qing dynasty between 17-19c. The mandarin speakers are war refugees brought by KMT in 1949.
It's believed that mainlanders took jobs in civil servants, military and teachers sectors, and enjoyed the benefits given by KMT, so they support KMT. The Min-nan speaking people controlled other sectors and felt oppressed by KMT. They funded DPP to struggle with KMT. Their struggle was the major news for 30 years and it is believed that KMT is lost now.
It is believed that KMT tried to ally Hakka and aboriginal people against Min people.
There are about 600k aboriginal people. They used to speak many languages related to Malay and Polynesian languages, and were not considered Han people. Today they are quite assimilated and integrated by Han people. But they still have poverty and health issues and live in bad locations.
Then there are about 500k "new immigrants" who came since 90s. 2/3 of them were PRC Chinese. 1/3 are Southeast Asians. Mostly are women who got citizenship by marriage. Then there are 500k Southeast Asian workers with visa only. I am not sure if this group should be further divided.
The unification issue affects the economic policy. KMT argues for closer economic ties with mainland: integrate the industrial system with China, technology transfer, open house for investment, supply products and produce to Chinese market, open door for talents to work on both sides.
DPP cautions against reliance on China: Secure technology and talents from them. Limit their investment on us. Set Southeast Asian countries as our partners instead of China.
We do have labor unions (old ones and new ones). But not labor parties. Both camps appeal to both the management and the labor votes.
There are also different opinions on welfare issue. The Pension Crisis and Health Insurance Crisis have been issues for years. But...I didn't remember them everyday.
Basically the KMT party is responsible for the pension for civil servants, military, and teachers in the past, and DPP attacks it.
I also heard that DPP were responsible for he pensions policy for other sectors, but I don't know if people like it or not.
On environmental issue, it's generally believed that KMT is more developmentalism and DPP is more environmental. I didn't pay much attention to that. KMT favors big industrial project (petrochemical and nuclear etc) and DPP opposes them.
In general they say that KMT is more conservative and DPP more progressive: gay marriage, sex education etc. but the main problem is that Taiwanese people strongly support death penalty but DPP opposes it.
That's about all I can say about it. They are all cliches spoken 100 times now but sometimes I speak them again for vanity.